Read the following passage and mark the letter A, B, C, or D to indicate the correct answer to each of the questions.
Which of the following statements is TRUE?
A. All the plants in a wood are eaten by animals.
B. All the animals in a wood depend on plants for their food supply.
C. Plants and animals in a natural community do not interact with their non-living surroundings.
D. The balance of a natural community means there is no primary species.